Attachment tool for reciprocating hammers



Feb. 3, 1942. F. J. PFEIFFER x-:T Al.

ATTACHMENT TOOL FOR RECIPROCATING HAMMERS Filed May 26, 1959 Feb. 3, 1942. F. J. PFEIFFER Erm.

ATTACHMENT TOOL FOR REGIPROCATING HAMMERS Filed May 2e,` 1939 Patented Feb. 3, 1942 ATTACHMENT Toor. Foa RECIPROCATING HAMMERS Fred J. Pfeier, Mount Prospect, Ill., and John Q. Kuhn, Newman, Kans.

Application May 26, 1939, Serial No. 275,810

Claims.

This invention relates to a tool for attachment to a pneumatic hammer or riveter and has for its most general object the provision of means to translate the reciprocating motion of the plunger of the hammer into a step by step rotation. A specic application which we have in mind, although it is not our intent to be bound by this particularity, is the use of the attachment tool in combination Wih a pneumatic rivet gun to tighten nuts on the bolts used to temporarily secure the parts together in the erection of steel structural Works.

A principal object of our invention is to provide an attachment for an ordinary pneumatic hammer, the combination of the two providing an impact wrench.

A second object is to extend and enlarge the usefulness of the ordinary pneumatic hammer or rivet gun.

A still further Objectis to obviate the necessity of separate air lines for a pneumatic hammer and for an impact wrench respectively.

A still further object is to provide a light weight inexpensive impact wrench.

Another obje-ct is to provide an attachment of the kind disclosed herein Which will act not only to turn the nut, but Which will deliver an impact blow at the location of the bolt to the members being secured together.

Other objects and purposes will be apparent from an examination of this specication.

In structural steel erection, plates and other members are temporarily secured in position by bolts and nuts. At present the tightening of the nuts is done either by a hand wrench, the plates being driven into close contact by hammer blows, or by an impact wrench operated other than by hand. These operations are followed by riveting, ordinarily done by a pneumatic hammer, commonly called a rivet gun. A reciprocating It shows primarily a suggested method of attachment to a conventional rivet gun.

Figs. 4 and 5 are respectively cross-sections on lines 4-4 and 5--5 of Fig. 1.

Fig. 6 `is a bottom plan view of the wrench socket.

In our attachment tool a casing I0 provides a frame. Protruding from the top of the casing is a plunger Il designed to be actuated by the plunger or reciprocating hammer of, for instance, an air driven rivet gun. The casing IIJ fits as a sleeve or collar over the end I2 of a conventional rivet gun, with the plunger II ttinginto said gun socket to receive the blows of the gun plunger in the gun strikes the required blows to clinch the rivet. We propose to provide an attachment for the ordinary rivet gun to translate a portion of the force of its blows into a twisting or turning force. This will permit the riveting vcrew to do the temporary bolting without the use of additional tools or air lines.

In the drawings,

Fig. l represents a side elevational view, but with the Wrench socket, a portion of the rivet gun, and a retaining collar shown in crosssection.

Fig. 2 shows a side elevation of the cam and ratcheting mechanism employed.

Fig. 3 is a cross-section on line 3 3 of Fig. l.

rdirection but not in the opposite direction.

hammer, not shown. A pin I3 is inserted through the casing I0 and in part through the stock of the gun end to secure the attachment to the gun, and to prevent the rotation of the attachment tool with respect to lthe gun. We do not expect to 'be limited to the particular method here shown of attachment of the tool to the gun. Various mechanical expedientsl can be employed so long as the attachment of the accessory tool is secure and its rotation in respect to the rivet gun prevented. Thus the rivet gun can be held in the hands of an operator in the manner usually employed.

The opposite end of the plunger II to that inserted in the rivet gun is provided with an enlarged ratchetv gear I4, the teeth I5 of which are so cut that a dog will ride over them in one A pair of driving shoulder cams I6 of substantial depth is angularly and integrally made in the ratchet gear head I4 of the plunger I I. A greater plurality of cams could be used if desired.

Shank Il is provided at its upper end with an enlarged ratchet gear I8 with its teeth shaped .as those of teeth I5 on the ratchet I4. Shoulder cams 2li are provided on ratchet gear I3 to cooperate with and to be actuated by the cams I6 on plunger I I.

The ratchet heads and enlarged ends of plunger I I and shank I'I are held in spaced relationship by spring 2| resting on bearing washers, in a central socket 22 provided in the members I4 and I8.

When the rivet hammer delivers a blow upon the end of plunger II, it will be seen that the cooperation of cam pairs I6 and 20 Will cause a slight rotation of shank I1. Upon the reciprocating of the hammer blow, the pressure exerted by spring 2| separates and places the parts in position for the next blow. The plunger II and shank I'I are prevented from reverse rotateeth I by springs 25.

tio-n by the ratchets |11 and |8 and their associated parts.

Collars 23 integrally made with casing II) secure dogs 24 which cooperate with the teeth I5 of ratchet I4. These dogs are mounted on pins 25 secured within collars 23 and through suitable openings in casing lli are pressed against These springs are secured in position by being wound once around pins 25 through suitable slots 21 cut within the dogs. One leg of each spring is conned within an annular groove cut within casing I0.

The dogs 24, of which we have provided four, are so spaced as to be in staggered or vernier relationship to teeth l5, as best shown in Fig. 4. Thus if a single blow of the hammer upon plunger II and its associated ratchet I4 does not turn the plunger and ratchet the full face of a tooth l5 there nevertheless will be at least one dog 24 to prevent any reverse rotation.

Two dogs 29, mounted on trunnions 3G, and lying in grooves 28 within casing IE), lcooperate with teeth I9 on ratchet I8 tov prevent counterrotation of shank I1. These dogs 29 are held in engagement with teeth I9 by springs 3| lying within grooves 32 provided in casing I0 and in the dogs 29, Dogs 29 and springs 3| are secured in place byy a retaining collar 33, which in turn is secured removably in place by screw 34.

The blows of the hammer of a pneumatic riveter are very rapid. Hence the rotation of shank I1 proceeds step by step with considerable rapidity even though each step may be only the distance represented by the face of one ratchet tooth.

The longitudinal movement apart of plunger I I and shank I1 with their respectively associated ratchets I4 and IB, caused by the action of the spring 2|, is limited by shoulders 35 and 33 formed by the enlarged diameters of the ratchets. Shoulder 35 on shank abuts against the end of the rivet gun when plunger I I is telescoped into the gun socket. Shoulder 3b on shank I1 is supported by springs |31 resting in part within sock- Y ets provided within shoulder |36 within casing l0 and integral therewith. Thus a blow of the rivet gun upon plunger I is transmitted to shank I1 save for that part of the blow which is absorbed by springs |31 and spring 2|. Shoulder |36 is so spaced in relation to shoulder 36 that u the blow of the rivet gun is not delivered to shoulder |36.

A reduction in diameter from ratchet IS forms shoulder 31 on shank I1. On the squared end of shank I1 and abutting against shoulder 31 a conventional wrench socket 33 is removably placed, and held in position by the usual spring snaps 39. It is obvious that the wrench socket can be changed to accommodate nuts of various sizes.

The blows given to plunger from the pneumatic hammer not only are converted into a step by step rotation of shank |1, as described, but the impact of the blow is delivered by shoulder 31 to the wrench socket 33. The face All of this socket in turn transmits the impact to the plates or members being secured together precisely at the area where such impact is most desired.

It will be observed that since both principal parts of our attachment tool, namely the driving plunger and the driven shank |1 are each free to rotate and to reciprocate within the casing Il), the tool, when attached to a rivet gun, functions as a partY thereof and does not have to be held against either motion. In addition the impact of the gun is delivered to the parts being secured together in the area of the bolt used for that purpose.

Our attachment tool may easily be carried by a riveter or other workman as part of his equipment. It is relatively light in weight and economical as compared with impact wrenches upon the market. Furthermore, with our attachment,

it is unnecessary to have an air line other than that which supplies the power for the rivet gun or hammer.

We claim:

l. The combination with a tool having a reciprocating hammer and a cylindrical barrel, of

an attachment therefor comprising a shell nonrotatably secured to said barrel, a rotary reciprocating plunger having a portion thereof eX- tending outwardly from one end of the shell and adapted to telescope within said barrel, a second rotary reciprocatory member having a portion thereof extending outwardly from the opposite end of the shell and' adapted to receive a wrench socket, means at the adjacent ends of the plunger and said'second member for rotating and reciprocating the plunger and" said member upon successive blows of the hammer, means to prevent rotation in one direction of said plunger and said second member in respect to the shell and means to transmit the blows of the hammer to the material being worked upon.

2. An attachment tool for use in connection with a mechanically operated reciprocating hammer for the purpose of converting the hammer to uses such as tightening bolts, said attachment tool comprising a hollow casing, a driving plunger slidably mounted in said casing, means on the casing to prevent rotation of said plunger in one direction relative to the casing, a driven plunger slidably mounted in said casing in alinement with the driving plungenmeans on the casing toprevent rotation of said driven plunger in one direction relative to the casing, means on said driven plunger to receive a wrench socket and to transmit blows thereto, means at the adjacent ends of the driving andv driven plungers and co-acting with each other to cause rotation of said plungers, and means tted between said plungers to hold them normally in partially spaced relationship.

3. An impact wrench for attachment to a tool having a reciprocating hammer, said wrench comprising a shell, a driving member fitted within the shell but with one end protruding therefrom to receive the blows of the reciprocating hammer of the tool, an angular shoulder cam upon the opposite end of the driving member, a driven member fitted Within the shell in alinement with the driving member but with one end protruding therefrom and adapted to receive a wrench socket, an angular shoulder cam upon the opposite end of the driven member adapted to co-act with the shoulder cam on the driving member upon successive blows ofk the reciprocating hammer of the tool, means to reciprocate the driving and driven members relative to the casing after each successive blow, ratchet teeth on the driving and driven members, dogs cooperating with said teeth and riding over them in one direction of rotation, means to limit the reciprocation apart of the driving and driven members, and means on the driven member to transmit the blow of the driving member to a wrench socket.

4. An attachment for connection with a tool having a reciprocating hammer, said attachment comprising a hollow shell, meansto non-rotatably secure said attachment to said tool, a driving plunger slidably mounted in said shell, an eX- tending end on said driving plunger adapted to be actuated by the reciprocating hammer, an enlarged head carrying ratchet teeth on said driving plunger, dogs cooperating with said ratchet teeth to prevent rotation in one direction of said driving plunger, a driven plunger slidably mounted in said shell in alinement with the driving plunger, an extending shank on said driven plunger adapted to receive a wrench socket, an enlarged head carrying ratchet teeth on said driven plunger, dogs cooperating with driving member, and means on the driven member for attachment of a tool designed to rotate.

said ratchet teeth to prevent rotation in one direction of said driven plunger, co-acting cam and shoulder means on the heads of the driving and driven plunger to transmit blows from the one to the other and to cause rotation of the plungers, means interposed between the driving and driven plungers to cause reciprocating movement apart thereof, a shoulder on the inside of said shell to retain the head of the driven plunger therein, yieldable supporting means between said head and said shoulder, and a shoulder on the shank of the driven plunger to cooperate with a wrench socket.

5. For a tool having a reciprocating hammer, an attachment for tightening nuts and the like comprising a cylindrical shell, a first reciprocating member in said shell actuated by the blows of said hammer, a cam and shoulder on the end of said reciprocating member remote from said hammer, a ratchet on said reciprocating member to prevent counter-rotation thereof, a second reciprocating member in said shell, a cam and shoulder on said second reciprocating member cooperating with the rst mentioned cam and shoulder, a spring compressed between the reciprocating members to separate them after a hammer blow, and means for attaching a wrench socket to said second reciprocating member adjacent a blow-transmitting shoulder thereof.

6. An attachment for a tool having a reciprocating hammer, said attachment comprising a casing, a driving member mounted therein to receive blows at one end from said hammer, a shoulder and a cam on the remote end of said driving member, a driven member mounted in said casing, a shoulder and a cam on said driven member cooperating with the shoulder and cam on the driving member to receive and to transmit straightline blows of said hammer and to cause rotation of said driven member, means between said driving and driven members to cause them to reciprocate with respect to each other, ratchet means to prevent counter rotation of the 7. A device for tightening nuts and the like comprising a hollow casing, reciprocating and rotating members mounted therein in longitudinal relationship to each other, a shoulder on the adjacent ends of said members to transmit blows of a reciprocating hammer, cooperating Cams on said shoulders to impart rotation to said members, means to return said members to normal longitudinal position after each successive blow, a ratchet to prevent counter-rotation, and a shoulder on one of said members to impart the hammer blows to a tool.

8. In a device for attachment to .a reciprocating hammer tool, a casing, a member to receive blows from said hammer, an enlarged remote end on said member within the casing andprovided with a blow transmitting shoulder, a cam, and a ratchet cooperating with the casing, a second member provided with a shoulder and a cam to cooperate with said first mentioned shoulder and cam to transmit the hammer blows and to rotate said second member, means between the two members to hold the shoulders of each out of engagement, and means to attach a tool-holding socket to the second member.

9. An attachment device for a tool with a reciprocating hammer, comprising a driving member mounted within a casing, a plunger on one end of said driving member to receive blows from said hammer, shoulder cams on the opposite end of said driving member, a ratchet gear on said driving member cooperating with the casing, a driven member, shoulder cams on said driven member cooperating with the shoulder cams on the driving member, compressible means between the driving and driven members normally holding said members in spaced relationship, and a shank on the driven member adapted to be fitted with a tool-holding socket and impart hammer blows thereto.

10. A device of the vcharacter described, comprising a casing, a rotary reciprocating driving member, mounted within the casing, a rotary reciprocating driven member mounted within the casing in alinement with the driving member, means at the adjacent ends of said members and cooperating with each other to cause step by step rotation of said members in respect to the casing, and means to transmit blows of the driving member to a shoulder on the driven member adapted to receive a working tool.

rFRED J. PFEIFFER.

JOHN Q. KUHN. 

